It is annoying to have to click "show X open more games" from dashboard, especially once you do that, it re-orders the games you have already seen. Is there any reason why it can't show all the open games from the get go? I guess if there are 200 or something it can't, but it rarely has more than 8 that aren't shown

I think the app only shows mega games from the your games page. From the dashboard page in website, a few games are show but then you can click to view them all.
If you want to see more games on the app use the open games page.